High-end quality and long life . High precision, Low noise 15 yearstrade experience Best price . Prompt delivery ZDF Thrust Ball Bearing 1.high load capacity 2.better lubricating condition 3.better impact-proof performanceBrand name ZDFSeriessingle, double and four rowsRings Materialbearing steel , carbon steelID size20-200mmOD size40-300mmQuality standardISO9001:2000 ISO14000PrecisionP0, ...